Backup applications use scratch media to process backup jobs that backup data. Scratch media are either new media or media that contain data that can be overwritten. In order for the backup jobs to execute properly, scratch media of the appropriate type must be loaded into the backup devices, such as tape libraries, used by the backup applications.
Currently, a user must manually estimate how much scratch media are needed for future backup jobs. If the user does not correctly estimate how much scratch media are needed before the backup jobs run, the backup jobs halt while awaiting additional scratch media to be loaded. The backup job may fail if the media are not loaded within a predetermined time period.
The manual estimating process may be highly complex. Over a given time period, hundreds of backup jobs may execute using backup devices located in multiple data centers. Each backup job may be a full or incremental backup of clients with varying data sizes. Additionally, the estimating process is further complicated by the use of media pools by the backup applications. Each backup job may be associated with one or more media pools and may not be able to access scratch media in other media pools. Therefore, the user must not only ensure that each backup device has the appropriate amount of scratch media loaded but also must ensure that each media pool contains the appropriate amount of scratch media to execute the backup jobs using that media pool. Because the estimating process is so complex, backup jobs often fail because the appropriate amount of scratch media has not been loaded.